Stem thermometers have a stem that can be inserted into a medium to measure its temperature. One popular use for stem thermometers is monitoring cooking food, especially meat. Throughout the specification, this use will serve as an example, even though the invention can be used to calibrate thermometers applied to many other purposes.
In cooking, a dial and a pointer of a stem thermometer indicate the temperature of the interior of the food. These thermometers need to be calibrated occasionally to ensure accurate temperature measurement and, in the case of food monitoring, optimum cooking of the food. An improperly adjusted or off-calibration thermometer can cause serious problems. In the case of meat cooking, undercooking can result in serious illness, while overcooking shrinks the meat and alters the flavor, making the meat less palatable.
Stem thermometers used in restaurants are sometimes calibrated by comparison with each other, which can lead to error if the comparison standard thermometer is off calibration. Testing laboratories calibrate thermometers with special equipment that is too expensive and cumbersome for restaurant use, though smaller and portable calibrators are available. Use of these calibrators involves holding the thermometer stem in thermal communication with a heat sink raised to a calibration temperature and using a wrench to turn an adjuster on the back of the thermometer to bring the dial and pointer into calibration.